WASHINGTON -- Two freshman Democratic senators, Joe Donnelly of Indiana and Heidi Heitkamp of North Dakota, have joined the growing chorus of lawmakers who say they support gay marriage.

In separate statements issued minutes apart, the two senators say their views on the issue have evolved. Donnelly says he reconsidered his opinion after recent Supreme Court arguments and public discussion on the issue.

Heitkamp says she now believes the federal government shouldn't discriminate against "people who want to make lifelong, loving commitments to each other."

Thursday evening, Florida Sen. Bill Nelson, also a Democrat, announced his support for gay marriage. That leaves only four Senate Democrats who have not endorsed gay marriage. Republican Sens. Mark Kirk of Illinois and Rob Portman of Ohio have also said they support gay marriage.